A velocity selector consists of two horizontal parallel plates producing a uniform downward electric field of magnitude \(E\) and a region of uniform magnetic field of magnitude \(B\) directed into the page, as shown in the figure. Ions of charge \(+q\) traveling horizontally to the right at speed \(v_0\) pass through the selector undeflected. The magnitude of the electric field is now increased to \(E' > E\) while \(B\) remains constant. How does the speed required for undeflected motion change, and in which direction will negative ions of charge \(-q\) entering at the original speed \(v_0\) deflect?